Will a book for blender 2.62 work for blender 2.78?
Most of the features and commands in 2.62 remain the same in 2.78.  None of the most important features have changed drastically.  Even for the features that have changed, the concepts and terminology used in the book should still be the same, and you should be able to find the new way to do it by a quick internet search.

Blender is remarkable in how backwards compatible it is, and how it doesn't change artists' workflow drastically from release to release.  The last major change was between 2.4 and 2.5, and even so almost all of the features remained close to the same from the artist's perspective. 

I remember learning Blender 2.6 with a book intended for 2.49.  99% of the book still worked in the new version, and for the remaining 1% I could Google the new way to do it.